Mercedes: altenator replacement, tension bolt, v belts

Question
o4 CLK 500    5.0L   replacing altenator do i need any special tools. will i run into unexpected issue.  
                      thanx,
                             Jay

Answer
Jay,
Disconnect both battery terminals ( - ) first and  reinstall in reverse order. It is a good idea to clean the post and terminals before reinstalling.  ( Remember that when the battery is disconnected, it will clear the computer memory and it may take several miles for the computer to relearn the sensors)
IF this vehicle uses a serpentine belt, just make a diagram of how it is reinstalled before removing. If V belts are used. Just make sure you track the belts off in sequence for proper return in reverse order.
When installing wires on the alternator, be sure to hold the terminals lock nuts while tightening the wire mounting nut. Do Not over tighten.
Check belt tightness before removing and try to achieve the same tension during reinstall.
My alternator uses a geared shoulder tension bolt to set the tension.  Just remember to count all your tools before and after the install before starting the vehicle.
If the voltage regulator is internal to the alternator that is OK. If the voltage regulator is an external unit, it is a good idea to replace that unit when the alternator is replaced. In fact some warranties are voided on the alternator if you do not replace the external unit too.

Good Luck, Let us know how it come out.
Rob